Projected capacitance is a form of touchscreen technology that offers increased accuracy, resolution and performance over its surface capacitance counterpart. In the past few years, device manufacturers have been transitioning to projected capacitance for these reasons. But not projected capacitance touchscreen devices use the same technology to identify and detect touch commands. Some use a special type of projected capacitance technology known as mutual capacitance.
What Is Mutual Capacitance?
Mutual capacitance is a form of projected capacitance touchscreen technology that identifies and detects touch commands by measuring the capacitance between two electrodes. When you touch the surface of a mutual capacitance touchscreen device, your finger will absorb some of its electrical current at the nearest intersection of the electrodes. As a result, the capacitance at that intersection decreases, allowing the device to register your touch command.
While invisible to the naked eye, mutual capacitance touchscreen devices feature a grid of intersecting electrodes in two layers. On one layer, electrodes are arranged vertically. On the other layer, electrodes are arranged horizontally. Because they are used together, these two layers of electrodes create a grid of intersecting electrodes.
Benefits of Mutual Capacitance
Mutual capacitance touchscreens offer several noteworthy benefits when compared to other touchscreens, one of which is improved accuracy. Since they measure capacitance at each electrode intersection, they are able to detect touch commands with greater precision than their counterparts powered by other forms of touchscreen technology. As a result, mutual capacitance touchscreens are a popular choice in applications where accuracy is needed.
In addition to increased accuracy, mutual capacitance touchscreens also support multi-touch commands. What does this mean exactly? A multi-touch command is any touch command that involves two or more simultaneous points of contact.
Many smartphones and tablets support multi-touch commands. A common example of multi-touch is the pinch-to-zoom function found in mobile devices. Pinching the screen essentially zooms in or zooms out the display. Not all touchscreens support multi-touch commands, but you can find this technology in mutual capacitance devices.
After reading this, you should have a better idea of mutual capacitance touchscreens and how they work. Basically, mutual capacitance is a subtype of projected capacitance touchscreen technology. It uses a grid of intersecting electrodes to detect touch commands by measuring capacitance. Touching the surface allows your finger to absorb some of the electrical current at the nearest electrode intersection, which the device detects as a loss of capacitance.